Our invention relates to curtain walls of buildings, and more specifically to a prefabricated curtain wall assembly composed of vertically alternating rows of standardized window units and spandrel units for attachment to the floor structure of a building, in particular of a multistory building. Our invention is also specifically directed to a method of installing such a prefabricated curtain wall assembly in place on a building.
A prefabricated curtain wall in the form of an array of discrete window units and spandrel units is per se not new in the art. Japanese Laid Open Patent Application No. 56-28956 represents a typical conventional example of prefabricated curtain wall which we believe is most pertinent to our invention. This prior art curtain wall comprises horizontal rows of spandrel units attached respectively to the floor systems (slabs and beams) of a building, and horizontal rows of window units arranged alternately with the rows of spandrel units so as to enclose the open spaces between the floor systems. Besides being connected to the spandrel units, the window units are coupled at their top ends to the floor beams of the building.
We favor the division of a curtain wall into separate window units and spandrel units, rather than into units each integrally comprising a window subunit and a spandrel subunit, as the separate window units and spandrel units are smaller in size, lighter in weight, and so easier of transportation and assemblage. We do, however, object to the direct attachment of both window units and spandrel units to the floor slabs and beams of a building. The direct mounting of not only the spandrel units but also the window units to a floor structure has made their installation very troublesome as the window units must also have had their vertical positions correctly adjusted with respect to the floor structure at the time of their mounting.